Detergent composition

ABSTRACT

IMPROVED DETERGENT COMPOSITIONS COMPRISING AN ANIONIC OR NONIONIC SURFACE ACTIVE AGENT AND, AS A BUILDER, A NOVEL WATER-SOLUBLE SALT OF COPOLYMER OF CYCLOPENTENE OR ITS DERIVATIVE WITH MALEIC ANHYDRIDE. SUCH DETERGENT COMPOSITIONS HAVE EXCELLENT DETERGENCY AND, IN ADDITION, HAVE A PRACTICALLY SATISFACTORY NON-IRRIATING PROPERTY ON SKIN AND EXCELLENT ANTISTATIC EFFECT ON THE WASHED MATERIALS AS WELL AS A SUPERIOR INHIBITING EFFECT ON RESTAINING. THE NOVEL WATER-SOLUBLE SALTS CAN BE READILY PRODUCED AT LOW COST AND THE PRESENT DETERGENT COMPOSITIONS CAN BE EASILY MANUFACTURED THEREFROM, SIMPLY BY MIXING WITH OTHER COMPONENTS.

United States Patent 3,830,745 DETERGENT COMPOSITION Haiime Tsukuni, and Shun Fujiki, Hitachi, and Teruo Tsunoda, and Yoichi Ooba, Tokyo, Japan, assignors to Hitachi Chemical Company, Ltd., and Hitachi, Ltd., both of Tokyo, Japan No Drawing. Filed Aug. 3, 1972, Ser. No. 277,501 Claims priority, application Japan, Aug. 3, 1971, 46/58,545 Int. Cl. C11d 3/04 US. Cl. 252-89 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates to detergent compositions. More particularly, this invention is concerned with a detergent composition, specifically for washing machines, which comprises a surface active agent selected from the group consisting of anionic surface active agents and nonionic surface active agents and a novel water-soluble salt of a copolymer of cyclopentene or its derivative with maleic anhydride.

Still more particularly, this invention is concerned with an improvement in a detergent composition comprising a surface active agent and a builder, characterized in that said surface active agent is a member selected from the group consisting of anionic surface active agents and nonionic surface active agents and said builder is a watersoluble salt of a copolymer of cyclopentene or a loweralkyl-substituted derivative thereof with maleic anhydride.

In recent years were proposed various kinds of improvements in construction and function of electric washing machines, which tend to provide a full-automatic washing machine. According to development of such new and improved models of washing machines, there has been increased in the art the demand for a new type of detergent composition which can wash at a time a wide variety of fibres without causing any damage thereupon and also has an excellent detergency even by relatively weak mechanical power.

Detergent compositions are generally composed of a surface active agent and a builder for enhancing or promoting activity of the surface active agent, together with a smal amount of each of a restaining inhibitor, bleaching agent, fluorescent dye, sizing agent and the like.

Representative examples of the builders which have been employed in the art for formulation of a detergent composition include inorganic builders such as carbonates, bicar'bonates, phosphates, polyphosphates, borates and silicates of alkali metals; and organic builders such as alkali metal salts and ammonium salts of aminocarboxylic acids, e.g., ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA). Of these builders is most widely employed sodium tripolyphosphate (hereinafter referred to as STP,) whichis typical of condensed polyphosphates.

Such condensed polyphosphates, a represenative of which is STP, show excellent builder effect, but they have 3,830,745 Patented Aug. 20, 1974 some drawbacks to be improved or overcome when used by incorporating them in a detergent composition. Stated illustratively, the polyphosphates, when used by incorporating them in a detergent composition, are often converted into lower condensed polyphosphate compounds through hydrolysis in an aqueous solution thereof, which leads to loss of their activity as a builder and thus results in lowering the detergent activity of the detergent composition. Also, liquid wastes containing such polyphosphate, upon flowing into rivers and/ or sewerage, tends to promote the growth of duckweeds, resulting in environmental pollution as well as spoiling of the beauties of the nature. The other conventional inorganic or organic builders render poor detergent activity to a detergent composition containing them because of their inherently poor activity.

As a result of our extensive attempts to reduce an amount of sodium tripolyphosphate to be employed or avoid the use of the above polyphosphate, it has been unexpectedly found that the above-depicted drawbacks in the prior art can be improved or eliminated by using as a builder a water-soluble salt of a copolymer of cyclopentene or its lower alkyl-substituted derivative with maleic anhydride (such copolymer of cyclopentene with maleic anhydride and copolymer of the cyclopentene derivative with maleic anhydride are hereinafter referred to as PM resin and PM resin derivative, respectively). This invention has been made upon the above finding and thedetergent composition of this invention is characterized in that it contains a Water-soluble salt of the PM resin or the PM resin derivative as a builder together with a surface active agent selected from the group consisting of anionic surface active agents and nonionic surface active agents.

It is, accordingly, an object of this invention to provide improved detergent compositions having advantageous properties.

It is another object of this invention to provide novel compounds which are useful as a builder for a detergent composition.

The foregoing and other objects, features and advantages of this invention will be apparent to those skilled in the art from the following description and apended claims.

The water-soluble salts of the PM resin and PM resin derivatives which may be employed as a builder in this invention are all novel compounds, which are white powders. Preferred-examples of these salts include the corresponding alkali metal salts, e.g., sodium, potassium and lithium salt; and the corresponding ammonium salts.

The PM resin and PM resin derivatives which are employable as a feedstock of the builder in this invention can be readily produced by copolymerization of cyclopentene or its lower alkyl-substituted derivative with maleic anhydride at a temperature of 50-150 C. in the presence of a radical polymerization initiator such as peroxide, e.g., benzoyl peroxide, azobisisobutyronitrile or the like and an organic solvent such as acetone, benzene or the like, as illustrated by the following reaction schema.

Radical polymerization g Olo LO R I] In the above formulae, R represents a hydrogen atom or a lower alkyl group, preferably of l to 5 carbon atoms, e.g., methyl, ethyl, n-prop'yl, isopropyl, n-butyl, sec.-butyl,

tert.-butyl, n-pentyl or the like and n is an integer of 1 through 15 inclusive. The PM resin and PM resin derivatives thus obtained are white powders and have an average molecular weight of 350-2,000 and a softening point of 200-260 C. The cyclopentene or its lower alkyl-substituted derivative, employed can be produced through hydrogenation of cyclopentadiene or its lower alkyl-substituted derivative, for example by the use of a nickelcontaining catalyst and gaseous hydrogen.

The water-soluble salts of the PM resin or PM resin derivative can be produced by reacting the PM resin or PM resin derivative obtained as above with alkali, for example, an aqueous solution of alkali metal hydroxide, ammonium hydroxide or alkali metal carbonate as illustrated by the following reaction schema.

In the above formulae, R and n are as defined above, M represents an alkali metal atom, e.g., sodium, potassium or lithium or an ammonium ion and M represents an alkali metal atom, e.g., sodium, potassium or lithium. In the above reaction, the aqueous solution to be employed may be of a concentration up to saturation, but may be usually of a concentration of 20-50% by weight for alkali metal hydroxide and ammonium hydroxide and of a concentration of saturation for alkali metal carbonate. The alkali metal hydroxide, ammonium hydroxide or alkali metal carbonate may be employed in an amount equivalent to that of maleic anhydride component of the PM resin and PM resin derivative. The reaction is conducted, while stirring, at room temperature for about 30 minutes to obtain a transparent reaction mixture. The reaction temperature may advantageously be elevated to 120-130 C., for shortening of the reaction period. The resulting reaction mixture is then subjected to distillation under reduced pressure and/or with heating (up to 120- 130 C.) to remove water therefrom. As a result, there is deposited a desired water-soluble salt of the PM resin or PM resin derivative. The product is white powders and its aqueous solution has an alkalinity of pH 9-10 at a concentration of 0.05% by weight.

Representative examples of the anionic surface active agents which may be employed in the detergent composition of this invention are, for example, sodium linear alkyl-benzenesulfonates (hereinafter referred to as LAS), sodium a-olefin sulfonates (hereinafter referred to as AOS), sodium 'alkylbenzenesulfonates (hereinafter referred to as ABS) and the like. Examples of the alkyl in the LAS and ABS and the a-olefin in the A08 are those having 10-20 carbon atoms, which may be alone or in mixture. Representative examples of the nonionic surface active agents which may be employed in the detergent composition of this invention are, for example, polyoxyethylene nonylphenyl ether with 8 moles of the linked ethylene oxide per mole (hereinafter referred to as PO-ENE-S), polyoxyethylene nonylphenyl ether with 20 moles of the linked ethylene oxide per mole (hereinafter referred to as POENE-20") and the like.

The water-soluble salt of the PM resin or 'PM resin derivative may be employed, as a builder, alone or in mixture with the other compound useful as a builder. Particularly, it is to be noted that the inorganic builders such as STP which have some drawback can advantageously be employed in a reduced amount by employing the present novel builder together therewith.

The detergent composition of this invention may be produced simply by mixing the components, i.e. a surface active agent, the present water-soluble salt and additives such as a restaining inhibitor, 'bleaching agent and the like. The present water-soluble salt may be incorporated in an amount usually employable in respect of the conventional builder, namely, in an amount of 10-90% by weight, preferably 40-60% by weight based on the detergent composition.

The detergent composition of this invention shows a high detergency as demonstrated by the following examples. In the examples, a washing efficiency D was determined according to the general detergency test procedure as set forth below:

Pieces of cotton broad cloth (yarn count #60) were subjected to desizing and then stained artificially by keeping them in contact with skin of person to prepare naturally stained cloths. The test cloths thus prepared were washed for 10 minutes in a tergotometer at 25 C. with a bath ratio (grams of cloth/grams of aqueous solution of detergent) of 30. In this procedure, reflectivity of test cloth prior to staining Ro, reflectivity of stained test cloth prior to washing Rs and reflectivity of stained test cloth after washing Rw were measured, respectively, and from the values thus measured the washing efficiency D (percent) was calculated according to the equation;

D=% (percent).

The following examples are given solely for the purpose of illustrating of this invention.

EXAMPLE 1 (1) Preparation of the PM resin 0.5 M01 (34 g.) of cyclopentene, 0.5 mol (49 g.) of maleic anhydride, 1 g. of benzoyl peroxide and 100 ml. of acetone were charged in a glass-made autoclave havinga capacity of 200 ml. The reaction was allowed to proceed at 80 C. for 2.5 hours. After completion of the reaction, the reaction mixture was cooled and then precipitated from methanol, followed by filtration and drying to give 65 g. of the PM resin which was white powders and had an average molecular weight of 1,500 and a softening point of 250-260 C.

(2) Preparation of the PM resin-Na salt 80 g. of the PM resin obtained above were added into g. of a 25% aqueous solution of sodium hydroxide, followed by stirring. After 30 minutes there was obtained a transparent reaction mixture. The thus obtained reaction mixture was subjected to distillation, employing an evaporator, under a reduced pressure of about 20 mm. Hg. to remove water, and then to further distillation, employing a vacuum pump, under a reduced pressure of 3 mm. Hg to completely remove water. As a result, there was obtained white, powdery PM resin-Na salt at a yield of 99%.

(3) Preparation of PM resin-K and NH salts The same procedures as described in (2) above were repeated except that 25% aqueous solutions of potassium hydroxide and ammonium hydroxide (amount twice molar amount of maleic anhydride component of the PM resin) were each employed in place of the aqueous solution of sodium hydroxide. There were obtained white, powdery PM resin-K salt and PM resin-NH salt at yields of 99% and 98%, respectively.

EXAMPLE 2 1) Preparation of methyl-PM resin 1.0 M01 (82 g.) of methylcyclopentene, 1.0 mol (98 g.) of maleic anhydride were dissolved in 200 ml. of benzene and 3.6 g. of benzoyl peroxide were then added. The reaction was allowed to proceed at 80 C. for 2.5 hours, while stirring. It was observed that viscosity of the reaction system increased with progress of reaction. After completion of the reaction, the reaction mixture was cooled to room temperature and then added in 360 g. of

methanol to deposit a white substance. The white substance was isolated by filtration and dried to obtain 140 g. of methyl-PM resin which has an average molecular weight of 1,600 and a softening point of 200-230 C.

(2) Preparation of methyl-PM resin-Na salt 90 g. of methyl-PM resin obtained above were added into 160 g. of a 25% aqueous solution of sodium hydroxide and heated, with stirring, at 50 C. for about minutes to obtain a liquid, transparent reaction mixture. The reaction mixture was subjected to distillation, employing an evaporator, under a reduced pressure of about 20 mm. Hg to remove water and subsequently to further distillation, employing a vacuum pump, under a reduced pressure of about 1 mm. Hg to completely remove water. There was obtained a desired product at a yield of 99%. The product was white.

(3) Preparation of methyl-PM resin-K salt The same procedure as described in (2) above was repeated except that an aqueous solution of potassium hydroxide (amount twice molar amount of maleic anhydride component of the methyl-PM resin) was employed in place of the aqueous solution of sodium hydroxide. There was obtained a white product.

EXAMPLE 3 (1) Preparation of n-propyl-PM resin The substantially same procedure as described in (1), Example 2 above was repeated except that equimolar amounts of n-propylcyclopentene and maleic anyhdride were employed. The thus obtained product was white powders and had an average molecular weight of 1,750 and a softening point of 185200 C.

(2) Preparation of n-propyl-PM resin-Na salt 0.5 M01 (55 g.) of n-propyl-PM resin were added into 420 g. of a 16.7% aqueous solution of sodium carbonate (0.5 mol of sodium carbonate) and heated, with stirring, at 50 C. for minutes to obtain a liquid, transparent reaction mixture. The reaction mixture was subjected to distillation, employing an evaporator, under a reduced pressure of mm. 'Hg to remove water and subsequently to further distillation, employing a vacuum pump, under a reduced pressure of about 1 mm. Hg to completely remove water. The evolution of carbonic acid gas was observed during the course of reaction. There was obtained the desired product, as white powders, at a yield of 97%.

EXAMPLE 4 (1) Preparation of ethyl-, isopropyl-, n-butyland n-pentyl-PM resins The substantially same procedures as described in 1) of Example 1, 2 or 3 were repeated except that the corresponding derivatives of cyclopentene to the above substituents were employed in an equimolar amount of that of maleic anhydride. The results are shown in the following Table 1.

(2) Preparation of ethyl-,isopropyl n-butyland n-pentyl-PM resin-Na salts The substantially same procedures as described in (2) of Example 2 or 3 were repeated except that each of the PM resin derivative obtained above and an aqueous solution of sodium hydroxide (amount twice molar amount of maleic anhydride of the PM resin derivative) were employed. There were obtained the desired Na-salts which were each White, powdery.

(3) Preparation of ethyl-PM resin-NH; salt The substantially same procedure as described in (2) of Example 2 was repeated except that an ethyl-PM resin and aqueous solution of ammonium hydroxide was employed. There was obtained the desired NH -salt which was white, powdery.

EXAMPLE 5 Detergency test was made according to the aforementioned general procedure with r.p.m. of the meter by the use of LAS as anionic surface active agent, POENE-8 as nonionic surf-ace active agent and watersoluble salts of PM resin and PM resin derivatives (which are polyelectrolytes) and sodium tripolyphosphate as builder and, after washing, test cloths were squeezed to remove moisture and then dried at room temperature. Formulation of each test detergent liquid is given below.

The results are summarized in the following Table II, wherein washing efiiciency of various detergent formulations is shown at the indicated German grade hardness (DH).

TABLE II Washing efliciency D (percent) Hard- Hard- Hardness ness ness Detergent formulation 0 DH 15 DH 30 DH 20.-.... Water 33. 8 33.0 32. 0 Aqueous solution of 0.05% PM 41. 9 35.1 33. 6

resin-Na. salt. Aqueous solution of 0.04% LAS. 51. 8 33. 3 28. 8 Aqueous solution of 0.04% 61. 3 55. 7 52. 7

POENE-80. Aqueous solution of (0.04% 65.3 56.3 55. 7

POENE-S plus 0.05% S'lP): Aqueous solution of (0.04% 71. 6 60. 0 58. 8

POENE-8 plus 0.05% PM resin-Na salt). Aqueous solution of (0.04% 81. 8 65. 6 36. 3

LAS plus 0.05% STP). Aqueous solution of (0.04% 80. 6 65. O 55. 5

13%) plus 0.05% PM resin-Na s A ueous solution of (0.04% 81. 1 65.4 45.6

AS plus 0.025% PM resin- Na salt plus 0.025% STP). Aqueous solution of (0.04% 74. 1 70. 2 40. 3

LAS plus 0.05% PM resin-K sa A ueous solution of (0.04% 65.3 60.3 38.7

AS plus 0.05% PM resin- N H4 salt). Aqueous solution of (0.04% 76. 9 60.4 51. 2

LAS plus 0.05% methyl-PM resin-N a salt). Aqueous solution of (0.04% 72.4 68. 3 39. 1

LAS plus 0.05% methyl-PM resin-K salt). A ueous solution of (0.04% 75. 1 59.2 50.1

AS plus 0.05% ethyl-PM resin-Na salt). Aqueous solution of (0.04% 63. 1 58.4 .37. 2

LAS plus 0.05% ethyl-PM resln-NH4 salt). Aqueous solution of (0.04% 73. 5 57. 4 48. 9

LAS plus 0.05% n-propyl-PM resin-Na salt). A ueous solution of (0.04% 73.2 57.3 48.5

AS plus 0.05% isopropyl- PM resin-N a salt). Aqueous solution of (0.04% 71.9 55. 3 46. 1

LAS plus 0.05% nbutyl-PM resmNa salt).

(") Aqueous solution of (0.04%

LAS plus n-pentyl-PM resin-Na salt).

Nora-C), and show a reference example, a comparative example and an example concerned with the present invention, respectively. shows weight percent based on the aqueous solution of detergent composition.

As is apparent from the above results, sodium salt of PM resin exerts, as such, detergency to some extent and a detergent composition having the present water-soluble salt incorporated therein as a builder for the surface active agent LAS or POEN'E-80, shows an excellent detergency, especially more remarkable in soft water. Even in highly hard water can be noted the same or higher degree I 7 of washing efficiency with the present detergent composition.

The novel water-soluble salts of the described copolymer are stable in the form of an aqueous solution and have a practically satisfactory non-irritating property on skin and an excellent antistatic eflFect on the washed ma terials as Well as a superior inhibiting effect on restaining. Moreover, the PM resin and PM resin derivatives are inexpensively avail-able due to recent development of petrochemical industries.

As can beseen from the foregoing, the present invention provided a detergent composition particularly suitable for full-automatic type electric washing machines, since a highly excellent detergency can be given by the use of a small amount of the detergent composition having the present novel water-soluble salt of the copolymer incorporated therein, regardless of the kind and type of the nonionic or anionic surface active agent employed.

What is claimed is:

1. A detergent composition comprising a surface active agent selected from the group consisting of anionic and non-ionic surface active agents and 10-90% by Weight of a builder, based on the amount of said detergent composition in which the builder consists essentially of water soluble alkali metal or ammonium salt of a copolymer of maleic anhydride and cyclopentene or a lower alkylsubstituted cyclopentene.

2. The improvement'as claimed in Claim 1, wherein said water-soluble salt is a member selected from the 8 p group consisting of an metalsalt andan a r nrriolnium salt. V

and n-pentyl. r

2000. y 5. The improvement as claimed in Claim 1,.Wh1:il1

said builder is present together with a builder otherthan said water-soluble salt of said copolymer. m

6. The improvement as claimed in Claim 5, wherein. said builder other. than said water-soluble salt of said;

copolymer is sodium tripolyphosphate.

References Cited UNITED STATES PATENTS WILLIAM E. SCHULZ, Primary Examiner us. 01. XJR. 252-Dig. 2

3. The improvement as claimed in Clainil, whereii'l' said lower alkyl is a member selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, -n-butyl 

